PSFK: Ingestible Robots Can Help Doctors Of The Future

Origami robot is capable of extracting objects or patching up small wounds

Researchers at the Massachusetts Institute of Technology have developed a tiny ingestible robot capable of unfolding from a biodegradable capsule in order to remove foreign objects—such as button batteries—from the stomach.

In collaboration with researchers at the University of Sheffield in the U.K. and the Tokyo Institute of Technology, MIT conducted experiments involving simulations of the human esophagus and stomach that showed the robot was capable of being steered by external magnetic fields to crawl across the stomach wall and remove small objects or patch wounds.

“It’s really exciting to see our small origami robots doing something with potential important applications to health care,” said Daniela Rus, a professor in MIT’s Department of Electrical Engineering and Computer Science who also directs the university’s Computer Science and Artificial Intelligence Laboratory, in a press release. “For applications inside the body, we need a small, controllable, untethered robot system. It’s really difficult to control and place a robot inside the body if the robot is attached to a tether.”

The robot is able to move using a ‘stick-slip’ motion — essentially meaning its legs stick to a surface through friction, but are able to slip free and move again when the body of the bot flexes and changes its weight distribution. It is made up of two layers of outer material, made of dried pig intestine like that used in sausage casings, that surround a biodegradable shrink wrap called Biolefin that shrinks when heated. When this middle layer contracts, the robot is able to fold.

In order to maneuver the robot, magnetic forces outside the body are applied to a permanent magnet situated in one of the bot’s accordion folds. The forces can make the robot spin in place, as well as pivot on one of its fixed feet. The magnet could also be used to pick up a button battery, as researchers demonstrated in their experiments.

According to MIT, 3,500 button batteries are reportedly swallowed each year in the U.S. Although they can sometimes be digested normally, at other times the hydroxide that is generated by an electrical current that can form outside the battery can burn esophageal or stomach tissue—in other words, removing them as soon as possible is important, and the researchers hope the robot will make that process less invasive.